Spent Fuel Hampers Efforts at Japanese Nuclear Plant

TOKYO — Workers at Japan’s ravaged nuclear power plant on Tuesday renewed a bid to bring its command centers back into service and to restore electricity to vital cooling systems, but an overheating spent fuel pool hampered efforts and raised the threat of further radiation leaks.

The storage pool at Fukushima Daiichi Power Station’s No. 2 Reactor, which holds spent nuclear fuel rods, was spewing steam late Tuesday, forcing workers to divert their attention to dousing the reactor building with water. If unchecked, the water in the pool could boil away, exposing the fuel rods and releasing large amounts of radiation into the air.

“We cannot leave this alone, and we must take care of it as quickly as possible,” Hidehiko Nishiyama, deputy director of Japan’s Nuclear and Industrial Safety Agency, told reporters.

Workers have now connected power cables to all six reactors at the plant, though some of the machinery, including the water pumps that cool the reactors, might be damaged, officials said, requiring more repair work. On Tuesday, Tokyo Electric Power Company, which owns the plant, said that power had been turned on in Reactor No. 3, but only for lights, not the cooling system.

The cooling systems at all of the reactors were knocked out by the March 11 earthquake and tsunami, and power was first restored to units 5 and 6. They were not operating before the quake but, like the other four reactors, have pools of spent fuel rods.

Another major effort was under way to restore full power and resume operations at the plant’s central command centers, which will make it easier for workers to monitor heat and water levels at the reactors. Recovery efforts have been hindered by difficulties in gauging readings of crucial data, forcing officials to work off aerial photos and speculation.

Workers also continued pumping water into three reactors with fire hoses, to keep them from overheating, while firefighters aimed streams of water at their spent fuel pools through gaps in the buildings housing the reactors, blown out in a series of explosions that rocked the site last week.

“We have not received validated information for some time related to the containment integrity of unit 1,” the official, Graham Andrew, said. “So we are concerned that we do not know its exact status.” He also said the agency lacked data about the temperatures of the pools holding spent fuel rods at the Nos. 1, 3 and 4 reactors. Another agency official said that the site continued to emit radiation but that the source was unclear.

Separately, the Kyodo news agency reported that the I.A.E.A. had detected radiation levels 1,600 times above normal about 12 miles from the plant. The government has ordered people to evacuate a 12-mile radius around the plant and told those 12 to 18 miles away to stay indoors.

The crisis has raised fears about the spread of contamination in the environment and the local food supply. The government has announced that traces of radioactive elements have been found in vegetables and raw milk from farms around the plant, prompting a government ban on shipments from those areas.

Elevated levels of radioactive iodine and cesium have also been detected in the seawater near Fukushima, and the government is testing seafood as a precaution, Yukio Edano, the chief cabinet secretary, said Tuesday. Government officials and health experts stress, however, that the doses are low and do not pose an immediate threat to human health.

Also on Tuesday, the public broadcaster NHK, citing the government’s Science Ministry, reported that radiation levels surpassing 400 times the normal level had been detected in soil about 25 miles from the Fukushima plant.

In the NHK report, a Gunma University professor said that radiation released by iodine 131 had been found to be 430 times the level normally detected in soil in Japan, and that released by cesium 137 was 47 times the normal levels. The professor, Keigo Endo, said that there was no immediate health risk but that the radiation levels would require monitoring.

The nuclear crisis has also overshadowed the monumental task in Japan of providing aid to hundreds of thousands of people displaced by the quake and the tsunami.

Photo

The nuclear crisis has overshadowed Japan’s other woes.Credit
The New York Times

More than 237,000 people remain in temporary shelters, NHK reported.

The Japanese Red Cross has 300 to 350 people assigned to medical teams working in the disaster zone, said a spokesman, Francis Markus. The organization is still scaling up its relief operations but planning is under way to help with recovery and reconstruction efforts, Mr. Markus said.

Medical teams are treating large numbers of cases of hypothermia and pneumonia, Mr. Markus said, as well as illness from swallowing polluted water. Doctors also are treating conditions tied to Japan’s comparatively older population, like diabetes and high blood pressure. The need for medicine is constant, Mr. Markus said.

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“One doctor in the field described the situation of receiving more medicine as pouring water in the desert,” he said.

Unseasonably cold weather has added to the daily struggle for evacuees and relief workers. Local forecasters are predicting overnight temperatures this week to hover around freezing in the prefectures hardest hit by the tsunami, in the northeast, as a cold front moves into the region.

On Tuesday, the government raised the official death toll to 9,079, and said more than 12,600 were missing, although officials cautioned that there could be overlap between the figures. The final death toll is likely to reach 18,000, the government has said.

The economy has also taken a battering. Honda and Toyota both said they would suspend domestic auto production until at least this weekend because of the difficulty of procuring parts.

Hiroko Tabuchi and David Jolly reported from Tokyo, and Kevin Drew from Hong Kong. Norimitsu Onishi contributed reporting from Tokyo.

A version of this article appears in print on March 23, 2011, on Page A14 of the New York edition with the headline: Fresh Crisis Halts Nuclear-Plant Repairs. Order Reprints|Today's Paper|Subscribe